Heat-shock protein 70-1 and HLA class II gene polymorphisms associated with celiac disease susceptibility in Navarra...

Heat shock proteins (HSP) are thought to play a role in the immune response making probable their contribution to celiac disease (CD). We studied the polymorphisms in the 5' regulatory region of the HSP70-1 gene and performed genomic HLA-DQ and -DR typing in 128 CD patients and 94 healthy controls from Navarra (Spain). The frequency of the C allele of the HSP70-1, characterized by the intermediate electrophoretic mobility of DNA, was significantly increased among CD patients (64.5% vs 37.2%. p <1 x 10(-7)). When subjects were stratified by the HLA II genotype, differences were statistically significant between DR3-negative or DR3-DQB1*02-negative CD patients and matched controls. Homozygosity for the DQB1*02 allele was present in 48.4% of CD patients and 12.8% of controls (OR = 6.4; CI:3.1 to 13.8; p <1 x 10(-7)). Similar increased risk was observed for DQB1*02/*02, DRB1*03/-, or DRB1*03/07 patients. Furthermore, those individuals expressing the classical HLA alleles in CD (DQB1*02/*02, DRB1*03/*07) who also carried the HSP70-1 CC genotype were twelve times more likely to develop the disease than the matched controls. We therefore conclude that although HSP70-1 gene does not seem to be primarily associated with CD, it might be a component of the high risk haplotype, playing a role as an additional predisposing gene for the disease.